1.3.1 Overview of VHTR Design Code System and Future Test Plan Using HTTR

摘要

High temperature gas-cooled reactor (HTGR) has currently strong interests of development worldwide. Besides its broad economical appeals resulting from unique high temperature capability, the reactor provides inherent and passive safety and aims at enhanced safety goal. JAEA has successfully built and operated the 30 MWt High Temperature Engineering Test Reactor (HTTR). JAEA is now performing development and validation of the analytical codes for the design and safety assessment aiming at the development of HTGR that has a high inherent safety and economy. These analytical codes will be verified by using the experimental data of the HTTR and of the out-of-pile test facilities. As for the experiment, we have been performing the HTTR safety demonstration test that is a reactivity insertion (control rod withdrawal) test, a coolant flow reduction test, and a loss of forced cooling (gas circulators trip) test. Enhancement of evaluation method for characteristics of a Very High Temperature Reactor (VHTR) has been studied to establish the VHTR technology in JAEA. In particular, a safety demonstration tests have been carried out to demonstrate inherent safety features of the VHTR using a High Temperature Engineering Test Reactor (HTTR) with which simulated abnormal status. In addition to that, safety analysis tools have been validated using the HTTR data. Appropriate safety margin can be assumed in the VHTR design by the safety analysis tools whose validation was carried out using the actual reactor data. These tools allow the design of the VHTR which is the one of the Generation-IV reactor type with high cost performance and high safety feature.